The present invention relates to the field of instruction-controlled digital computers and specifically to methods and apparatus whereby the console communicates with the remainder of the data processing system.
In data processing systems, control functions are typically implemented in terms of a fixed sequence of instructions called a program where the instructions are sequentially fetched from storage, are decoded and are executed to carry out desired data manipulations.
While some prior art systems have provided techniques for interrupting the operation of the data processing system by human intervention, for maintenance, or other reasons, such interruption techniques have not provided the flexibility which is desirable for a more efficient use of data processing systems.